A number of prior art devices are known in which a sound output is obtainable by igniting apparatus generally similar to engine combusion chambers thus to give an explosive output. In most cases, these devices emit only a single sound and are not operable in synchronous relationship to electromagnetic energy. One system of this type is shown and described in R. J. Marotta, U.S. Pat. No. 2,917,736, issued on Dec. 15, 1959 for a "Pest Control Device". A similar device used to emit a single loud sound to repel birds, animals, or pests is shown and described in R. M. Lewis et al, U.S. Pat. No. 3,412,394, issued Nov. 19, 1968 for "Photocell Controlled Pest, Bird, and Animal Chaser". In that system again the actuation of the device is controlled by a photocell with a single activation of the combusion chamber resulting. A still further sound emitting device is shown in F. M. Lindley's U.S. Pat. No. 3,113,304, issued on Dec. 3, 1963, for a "Pest Control Device".
The present invention is generally based upon the concept described in U.S. Pat. No. 4,356,753, issued on Nov. 2, 1982 and entitled "Musical Electromagnetic Analog Synthesizer Controlled Rocket Engine". This device was invented by Paul L. Galley, and assigned to Andre F. Koerner, the present inventor. This assignment is recorded at Reel 4160, Frames 568-570 in the U.S. Patent and Trademark Office under a date of Aug. 22, 1983. This patent describes a musical instrument combination including a rocket engine type combustion chamber and a system for firing it either by a single drum beat control or by variable frequency control pulses. The effect achieved by the rocket engine output sound is similar to that of a pipe organ and resonator and further is of a pitch controllable by the barrel length and diameter of the rocket engine chamber exhaust structure. This device, however, was not made particularly adaptable to industrial applications. Futhermore, the device as described in this patent emitted a sound of principally low frequencies and for only a short period of time. The present invention is a distinct variation on the concept described in the above-identified patent.
It is an object of the present invention to provide a sound engine whose sound output, specifically amplitude and frequency, may be accurately controlled.
It is an object of the present invention to provide a sound engine that is capable of producing extremely loud sounds in relation to the size of the sound generator package.
It is another object of the present invention to provide a sound engine that is capable of producing a wide range of sound frequencies including those in excess of 2,000 Hertz.
It is another object of the present invention to produce an extremely loud sound while using relatively small amounts of electrical power.
It is another object of the present invention to provide a sound engine that is capable of a variety of industrial applications such as cleaning systems, alarm systems, and testing systems.
It is still a further object of the present invention to provide a sound engine that is capable of long-term operation.
These and other objects and advantages of the present invention will become apparent from a reading of the attached specification and appended claims.